The invention relates to a method for protecting a vehicle occupant in a vehicle seat of a vehicle, wherein at least one protection element mounted on the vehicle seat and capable of being triggered to protect the vehicle occupant sitting on the vehicle seat is triggered when a collision is imminent or occurs.
German Patent Document DE 10 2005 032 033 A1 describes a restraint system for vehicle occupants, comprising a vehicle seat, the back rest of which is laterally bounded by at least one side wall, wherein the transition from a front side of the back rest to the side wall forms a support surface for a vehicle occupant, and further comprising a air bag module, the air bag of which is accommodated in a folded state in the back rest of the vehicle seat and the unfolding direction of which is oriented towards the support surface.
German Patent Document DE 197 502 23 C2 describes a method for the driving situation- and driving style-related adaptation of the lateral support of a person sitting in the seat of a vehicle, in particular a passenger car, wherein a transverse acceleration acting on the seat is determined as a reference value for the adaptation, and the determined transverse acceleration is weighted by the current travelling speed of the vehicle and a control variable for the amount of the adaptation is derived therefrom.
International Patent Document WO 2008 110 610 A1 describes a vehicle seat arrangement for a motor vehicle and a method for protecting a vehicle occupant, comprising a vehicle seat, at least one inflatable element mounted on the vehicle seat for the protection of a vehicle occupant sitting on the seat, means for inflating the inflatable element, which inflate the inflatable element in response to a control signal indicating a collision of the motor vehicle or an imminent collision of the motor vehicle with an object, wherein the inflatable element is designed and arranged such that, while it is being inflated in response to the control signal, it applies a pulse to the vehicle occupant which moves the vehicle occupant away from a collision section of the motor vehicle which collides or will collide with the object.
European Patent Document EP 1 698 521 A1 describes a device and a method for protecting a vehicle occupant in a vehicle.
Exemplary embodiments of the present invention are directed to a method for the control of a vehicle occupant restraint system which is improved in comparison to prior art.
In the method according to the invention for protecting a vehicle occupant in a vehicle seat of a vehicle, in particular a passenger car, at least one protection element mounted on the vehicle seat and capable of being triggered to protect the vehicle occupant sitting on the vehicle seat is triggered when a collision is imminent or occurs. According to the invention, a reversible belt tensioner assigned to the vehicle seat is triggered at a time before a triggering of the protection element, and while or as the protection element is triggered, a resulting belt tensioning is released again.
The method according to the invention ensures that the vehicle occupant is moved into a position suitable for the triggering of the protection element, e.g., an inflatable or movable protection element such as a lateral cushion or support, and held there for a short time, and that, by releasing the belt tensioning, for example by deactivating a retractor, he/she becomes once again movable in good time, so that, by triggering the protection element, a motion impulse or an impetus can be applied to the vehicle occupant, whereby an increase of the distance between the vehicle occupant and a collision section of the motor vehicle which collides or will collide with the object is achieved.
As a result of an early application of the motion impulse to the vehicle occupant, who has been brought by the preceding belt tensioning into a position suitable for the absorption of the motion impulse or impetus, e.g., into a customary upright seated position, and who is seated freely movable owing to the retractor being, for example, deactivated while or as the motion impulse or impetus is triggered by the protection element, an acceleration acts on the vehicle occupant before the occurrence of a collision, whereby a subsequently acting crash energy at a collision, i.e., the absolute value of the crash energy and thus a stress and/or acceleration maximum of the vehicle occupant, is reduced.
In a conventional vehicle seat, the vehicle occupants would be accelerated with a time delay owing to the elastic properties of the vehicle seat and/or a distance from the vehicle seat, for example by a forward displacement of the vehicle occupant as a result of braking in case of a collision hazard. This delayed acceleration results in further stress and/or acceleration maxima of the vehicle occupant. This is securely avoided by the present invention, thereby reducing occupant stress.
In a particularly advantageous embodiment, the belt tensioner is triggered at a time before a triggering of the protection element, e.g., an inflation of an inflatable element or a movement of a movable element. As a result, the vehicle occupant, or at least a section of the body of the vehicle occupant, is moved towards the back rest of the vehicle seat and held there. This avoids the delayed acceleration resulting from the forward displacement of the vehicle occupant.
In a particularly advantageous way, the inflatable element or the movable element applies, while being inflated or moved in response to the control signal, an impulse, in particular a motion impulse or impetus, to the vehicle occupant or at least a section of the body of the vehicle occupant, whereby the vehicle occupant or at least a section of the body of the vehicle occupant is moved away from the collision section of the motor vehicle which collides or will collide with the object. This increases a distance between an estimated collision point and the vehicle occupant. By combining a pre-triggering of the belt tensioner and a subsequent triggering of the protection element while the retractor is deactivated, in particular in an event-related manner, it is ensured that the vehicle occupant can absorb the motion impulse. In other words, as a result of the deactivation of the retractor and the resulting release of the belt tensioning as or while the protection element is triggered, the motion impulse or impetus applied by the triggered protection element can be absorbed by the vehicle occupant without being inhibited by the retractor.
The vehicle occupant is moved towards the interior of the vehicle and thus away from the deforming lateral region of the vehicle, for example the door lining or the B post, by the inflated or moving element.
The motion impulse or impetus applied to the vehicle occupant by the inflated or moving element expediently meets the vehicle occupant in the rear position after being moved by the belt tensioner towards the back rest of the vehicle. As a result, the whole surface of the inflatable element can act on the vehicle occupant or at least on a body section of the vehicle occupant. The movable side wall can therefore optimally act on the vehicle occupant or at least on a body section.
The restraint of the vehicle occupant therefore begins much earlier than with a conventional restraint system. In addition, the vehicle occupant participates as early as possible in an acceleration by the triggering of the protection element, in order to avoid acceleration peaks.
No substantial relative speed is built up between the inflatable element and the vehicle occupant. As a result, the relative speed between the vehicle occupant and the lateral region of the vehicle always remains lower than in a conventional protective device with an occupant restraint system.
In a particularly advantageous embodiment, the invention allows an inflation of the inflatable element or a movement of the movable element and thus a moving away of the vehicle occupant from the collision point in particular in response to a so-called pre-crash signal, before the vehicle actually collides with the object. By the inflating or moving element, the vehicle occupant is moved out of his/her seated position away from the collision section of the vehicle, i.e., the collision point, generating an additional distance between the vehicle occupant and the collision point. This additional distance represents an additional absorption distance, whereby the effects of the collision on the vehicle occupant are reduced. In addition, as the vehicle occupant moves away, the relative speed between him/her and the vehicle structure intruding into the vehicle interior owing to the collision can be reduced. In this process, the distance travelled by the vehicle occupant away from the collision point towards the vehicle interior can be used as an additional deformation distance in the event of a collision.
Embodiments of the invention are explained in greater detail below with reference to drawings.
Corresponding parts are identified by the same reference numbers in all figures.